Archery is an ancient art replete with efforts to provide improved structures contributing to efficiency and ease of handling of archery instruments and overall accuracy in their use.
One technique for achieving improvements in archery entails concepts for reducing the holding force when a bow string is extended, so as to reduce the strain imposed upon an archer as he is readying the release of an arrow and taking aim. This basic concept is described, for example, in pages 53, 63 and 67 and in other portions of an article entitled "Archery", edited by Hickman et al and published by the National Field Archery Association in 1947.
An effort at utilizing this prior at concept is set forth in a previous Allen U.S. Pat. No. 3,486,495. However, the Allen system is characterized by a compound pulley and multiple pulley line system which creates a structural arrangement where multiple pulley strings are interposed between a bow string nocking zone and a bow hand grip.
The present invention departs entirely from the Allen concept and provides a technique for improving efficiency and handling in archery instruments by utilizing a multi-directional energy storing system.
It is a principal object of the invention to provide energy storing means extending longitudinally along bow limb means in such a manner as to not obstruct a nocking zone and maintain a single bow string extending between the tips of the bow limbs.
It is also an object of the invention to provide a unique, eccentrically mounted, force transmitting, cam-lever means, which as an optional objective, may be selectively detachable if desired so as to permit the "tailoring" of bow characteristics to the requirements of individual archers. Yet another, and optional, object of the invention is to provide, through the cam-lever means, a mechanism which will indicate to the archer the optimum termination of bow string pulling, i.e., provide in essence a pull "stop".
Another object of the invention is to provide an energy storing system of the type heretofore described which is characterized by a relatively low distension of energy storing means so as to minimize release reaction force generated movements.
In accomplishing at least some of these basic objectives the invention contemplates an archery apparatus including a limb and hand grip assembly comprising a first limb structure, a second limb structure, and a hand grip structure. The hand grip structure interconnects the first and second limb structures, with the first and second limb structures extending generally oppositely away from the hand grip structure. A bow string structure extends between the first and second limb structures and provides a nocking zone operable to engage an arrow.
The improvement of the present invention comprises a multidirectional energy storing and release system including an energy storing assembly having first elongate energy storing means, extending longitudinally along at least one of the limb means and other elongate energy storing means extending longitudinaly along this limb means. An energy transfer means is operable to interconnect the first and other elongate energy storing means in force transmitting communication and afford a multidirectional storage and releasing of energy.
An anchor means may connect a first end of the interconnected first and other elongate energy storing means with the limb and hand grip assembly. A force transmitting, connecting means connects a second end of the interconnected first and other elongate energy storing means with one end of the bow string structure. Stressing means are also provided which are operable in response to the imposition of pulling force on the bow string structure to stress the first and other elongate energy storing means in multiple zones, extending longitudinally of the limb means, and thereby store energy in multiple zones along the limb structure. The stressing means is also operable, in response to the release of said bow string structure, to release the energy stored in multiple zones by the first and other elongate energy storing means. During this release, energy stored in the first and other elongate energy storing means is transmitted longitudinally of the limb structure through one of the first and other elongate energy storing means, transversely of the longitudinal directions of the first and other energy storing means and through the energy transfer means to the other of the first and other elongate energy storing means and through the energy transfer means to the other of the first and other elongate energy storing means, longitudinally of the other of the first and other elongate energy storing mens, and through the force transmitting connecting means to the bow string structure.
The release of energy through the first and other elongate energy storing means is effected in directions extending generaly longitudinally of the limb means. The release of energy from the first and other elongate energy storing means is further effected remote from said nocking zone and remote from an area between the nocking zone and the hand grip means. Moreover, the first and other energy storing means cooperate with the bow string means to provide a substantially unobstructed area between the bow string structure and the hand grip structure.
The invention may further embrace such an archery apparatus wherein, in response to said pulling of said bow string means, energy is stored in each of the first and second elongate energy storing means in response to elongate distension of each of the first and second elongate energy storing means not exceeding about five percent of the length thereof.
The invention also contemplates an apparatus including an eccentric system having a member pivotally and eccentrically supported on the limb and hand grip assembly and operable to pivot about an axis extending generally transversely of the pull direction of the bow string structure. This eccentric member may comprise a cam means. A pivot means pivotably mounts the eccentric member, is spaced from the pivot means and disposes the eccentric member and the bow string structure in force transmitting communication. A second securing means, carried by the eccentric member, is spaced from the pivot means and dispose the eccentric member in force transmitting communicaton with the anchor means. A first follower means is connected in force transmitting communication with the bow string structure to translate along a first periphery porton of the eccentric member in response to pulling of the bow string structure, with this first periphery portion defining first lever arm means upon which force is exerted by the bow string structure. A second follower means is also provided which is connected in force transmitting communication with the energy storing assembly and is operable to translate along a second periphery portion of the eccentric member in response to pulling of the bow string structure. This second periphery portion defines second lever arm means upon which force is exerted by the energy storing assembly in a direction extending longitudinally of the limb means.
Other independently significant aspects of the invention relate to particular mounting and location arrangements for the eccentric member and energy transfer means, particular energy storing arrangements, and to bows wherein each of the bow limb structures has an eccentric system and a multi-directional energy storing and release system associated therewith and where means may be provided to coordinate the movements of the eccentric members associated with each limb structure.